It is an older study so we have to give the researchers a break for promoting low fat meals, instead of meals low in saturated fat.
For the intervention a heart symbol was placed on certain menu items that were lower in fat and thus "healthier." This was based on the science we had at the time. The researchers planned to collect sales data at baseline (before the labels) and after the labels. They would check to see if the proportion of labeled items sold to non labeled items increased.
They had a nice research design in mind. Their plan included NOT labeling menus at one of the restaurants - at least not at first. They wanted to compare the results to a "control" group. It is similar to a drug study where two groups are alike but one gets the drug and the other doesn't and then you check some outcome, like blood pressure. IF the drug group has better BP, you have reason to believe it was the drug that made the difference. SO, if the percent of low fat menu items sold increased in the restaurant using the labels as compared to the other, then it suggests that the labeling caused the increase. Got it?
The second design feature that they planned to use was taking away the labels to see if the sales of those items stayed the same or decreased. If they decreased, that would add evidence to the importance of the labels.
Well - these two features just didn't happen. They didn't happen because the restaurant managers would not cooperate and that is the encouraging part of this flaw!
The restaurant manager of the store that was not supposed to use labels used them anyway - without checking with the researchers first. In all restaurants, when it was time to remove the labels, no one wanted to. This supports the idea that both customers and restaurant owners/managers find value in identifying healthier items.
Of note - I did check back on the FDA website today to see if another report had been filed on the status of implementing sec 4205 of the ACA - i.e. the menu labeling law. I found one sentence dated June 13, 2012.
Policy options in response to comments on the proposed rule are under consideration.